Answer
As $a$ increases, so does the slope. Interestingly, the rate of change is the same as the slope in linear functions. The inverse happens when $a$ decreases.
Work Step by Step
Slope and rate of change are practically the same in linear functions since they use the same equation ${f(b)-f(a) \over b-a}={y_{2}-y_{1} \over x_{2}-x_{1}}$
